This page
http://www.teamxray.com/teamxray/news/n ... goria=1350, I think has all the necessary information
![Smile :)](./images/smilies/icon_smile.gif)
As you can see there is no exact match between the 2 spring versions
"The unique characteristics of these new springs makes it difficult to make
direct comparisons with existing „color-coded“ XRAY springs. The table
below approximates where the new black springs would possibly fall within
the range of current springs (based on stiffness); however, the new springs
will give the car slightly different handling characteristics."